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The work is published in the journal ACS Nano and in it those responsible also suggest that vaccine boosters could be necessary for everyone in the future.
The work is published in the journal ACS Nano and in it those responsible also suggest that vaccine boosters could be necessary for everyone in the future.
Both messenger RNA vaccines cause the immune system to produce antibodies against the receptor binding domain or RBD and Two doses are necessary to provide immunity to people who have not previously suffered from covid-19.
The RBD, which is within the Spike protein, is the part of the virus that attaches to host cells.
The American Chemical Society recalls in a statement that Very few people participated in clinical trials who had already recovered from the disease, so the immune response of these individuals is less known.
Furthermore, he adds, the time course of antibody development in both groups has not been well characterized, nor how long virus-neutralizing antibodies persist.
Therefore, Otto Yang and his colleagues at the University of California (USA) wanted to compare the levels, quality and persistence of antibodies after one and two doses of the messenger RNA vaccine in people with or without previous SARS-CoV-2 infection.
Researchers used an enzyme-linked immunosorbent assay to measure antibodies against RBD in subjects who received the Pfizer-BioNTech or Moderna preparations and in unvaccinated people shortly after mild or severe cases of covid-19.
In the 28 participants without previous infection, a dose of either Vaccines triggered antibody levels similar to those observed after mild covid-19 infections, while two doses were needed to obtain antibodies against RBD that approached those observed after severe cases.
By contrast, In 36 participants who had Covid-19 before vaccination, the first dose produced a strong antibody response similar to severe natural infection, but the second dose did not provide any additional increase in antibody levels.
The quality of these, indicated by their ability to neutralize the SARS-CoV-2 Spike protein and their potency (the one the virus uses to enter the cell) followed similar patterns.
After the second dose of the vaccine, antibody levels decreased in both groups in a manner comparable to natural infection, with a average loss of 90% in 85 days.
Although more research is needed on the T cell response to vaccines - another arm of the immune response - this result suggests that booster vaccines are probably needed for everyone, the researchers conclude.
